Which country holds the record for being the most densely populated nation in the world?
And the answer: Monaco.

As the second smallest country in the world, Monaco covers about 2 square kilometers, or less than one square mile. With more than 37,000 people living in that small area, this makes Monaco the most densely populated country in the world, with Singapore coming in second.
Though small by size, Monaco is well known by tourists and millionaires alike. Home to some of the most extravagant events of the year, such as the Monaco Grand Prix, this coastal city-state thrives in its ability to attract the attention (and funding) of some of the wealthiest individuals around the globe. It also is known for gambling, a reputation which helps fund the country's continued lavish way of life even without the imposition of income taxes. In fact, Monaco is often referred to as "Billionaires' Playground."
At just less than one square mile (smaller than Central Park in New York City), Monaco is home to over 12,000 millionaires. This means roughly one out of every three residents is a millionaire (32% of the population). Interestingly, though the millionaire residents are a significant portion of the population, all Monaco residents are forbidden by law from participating in the city-state's gambling, leaving ample room for tourists to spend as much as they please. But, according to a CIA World Factbook, Monaco is not any worse for the wear: 0% of its residents reside below the poverty line.
Monaco has been under the authority of the Grimaldi family line for over 700 years. It has been governed under a constitutional monarchy since 1911, with the Sovereign Prince of Monaco as head of state. Check out the video below to learn more about this expensive and tiny city-state:
